Mercury is a planetary misfit, an oddball in the solar system, and this month the BepiColombo mission is setting off to study it in unprecedented detail.
The best images we have of Mercury are from NASA's MESSENGER mission, which pictured its cratered surface and curious features earlier this decade.
​Soon, the joint European and Japanese BepiColombo mission will head there to take an even closer look.
Watch the launch of BepiColombo live on 20 October 2018 at 1:45 GMT